An apparatus of evaluating a layer matching deviation based on CAD information of the invention, is provided with means for storing CAD data and a function of displaying to overlap a scanning microscope image of a pattern of a semiconductor device formed on a wafer and a design CAD image read from the storing means and a function of evaluating acceptability of formation of the pattern by displaying to overlap a pattern image of the semiconductor device formed on the wafer and the design CAD image of the pattern, in addition thereto, a function capable of evaluating acceptability of formation of the pattern also with regard to a shape and positional relationship with a pattern formed at a later step by displaying to overlap a design CAD image of the pattern formed at the later step.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A method of evaluating a deviation between patterns successively formed on a wafer to fabricate a semiconductor device, comprising the steps of: storing CAD data used to form the successively formed patterns of the semiconductor device; obtaining an image with a microscope of an already formed one of the patterns on the semiconductor wafer; displaying the image obtained with the microscope on a monitor; reading first CAD data used to form the already formed pattern of the semiconductor device; displaying the first CAD data with the displayed image of the already formed pattern as a first overlapped image on the monitor to enable evaluation of a deviation in formation of the already formed pattern; reading second CAD data to be used to form a successive pattern of the semiconductor device that will be connected to the already formed pattern; and displaying the second CAD data with the displayed image of the already formed pattern and the first CAD data as a second overlapped image on the monitor to enable evaluation of a deviation of the successively formed pattern from the already formed pattern.
2. A method of evaluating a deviation between patterns according to claim 1 ; further comprising the step of forming the successively formed pattern based on the second overlapped image.
3. A method of evaluating a deviation between patterns according claim 2 ; wherein the step of obtaining an image with a microscope of an already formed one of the patterns comprises the step of obtaining the image with a scanning microscope.
4. A method of evaluating a deviation between patterns according to claim 1 ; wherein the step of obtaining an image with a microscope of an already formed one of the patterns comprises the step of obtaining the image with a scanning microscope.
5. A method of evaluating a deviation between patterns according to claim 1 ; wherein the successively formed pattern that will be connected to the already formed pattern comprises a pattern used to form a layer of material at least partially covering the already formed pattern.
6. A method of evaluating a deviation between patterns according to claim 1 ; wherein the step of obtaining an image with a microscope of an already formed one of the patterns on the semiconductor wafer comprises the steps of designating a desired region of the wafer containing a predetermined pattern, and acquiring low magnification pattern image data of the predetermined pattern from the image obtained by the microscope by controlling an observation position of the microscope so that a center of observation of the predetermined pattern falls in a predetermined observation field of view.
7. A method of evaluating a deviation between patterns according to claim 6 ; further comprising the steps of sampling an edge of the predetermined pattern contained in the low magnification pattern image data and outputting edge line segment data.
8. A method of evaluating a deviation between patterns according to claim 7 ; wherein the step of reading first CAD data comprises the step of obtaining CAD line segment data of the already formed pattern corresponding to the low magnification pattern image data.
9. A method of evaluating a deviation between patterns according to claim 8 ; further comprising the step of calculating a deviation amount between the center of observation of the microscope and a center of the predetermined observation field of view by comparing the CAD line segment data and the edge line segment data.
10. A method of evaluating a deviation between patterns according to claim 9 ; further comprising the step of controlling a position of a sample stage of the microscope based on the calculated deviation amount such that the center of observation of the microscope and the center of the predetermined observation field of view coincide with each other.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
May 16, 2002
June 29, 2004
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